Automatic stop-motion.



G. JOHN & D. L. LINDQUIST.

L AUTOMATIC STOP MOTION.

APPLICATION FILED AUG.9. 1911..

Patented Nov. 9, 1915.

4 SHEETS-SHEET I.

.IIIIII? v[ WW/es Y ZNW G. JOHN & D. L. LINDQUIST.

AUTOMATIC STOP MOTION. APPLICATION FILED AUG-9. 19n.

Patented NOV. 9, 1915.

SHEETS-SHEET 2.

6 JOHN & D. L. LINDQUIST. AUTOMATIC STOP MOTION.

APPLICATION FILED AUG-9. 19H.

Patented Nov. 9, 1915.

4 SHEETS-SHEET 3.

llll I lu'lll I I I I I llll G. JOHN & D. L. LINDQUIST.

AUTOMATIC STOP MOTION.

APPLICATION FILED AUG-9. 91!.

1,159,587. Patented Nov. 9, 1915.

4 SHEETS-SHEET 4.

UNITED STATES PATENT argon.

GRIFFITH JOHN AND DAVID L. LINDQUIST, 0F YONKERS, NEW YORK, ASSIGNORS TO OTIS ELEVATOR COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

AUTOMATIC STOP-MOTION.

Application filed Au gust 9.

To all whom it may concern Be it known that we. GRIFFITH JOHN, a subject of the King of England, and DAvn) L. LINDQUIST, a subject of the King of Sweden, residing at Yonkers. in the county of Westchester and State of New York, have invented a new and useful Improvement in Automatic Stop-Motions, of which the following is' a specification.

Our invention relates to automatic means for effecting the stopping of an elevator car. and more particularly to an adjustable automatic stop motion switch mechanism mounted on the car in any convenient position and operated through the medium of pinions, racks, levers, or other suitable mechanism, by adjustable cams mounted in the hatch way, usually near the top and bottom thereof.

The automatic stop motion switch may perform the same functions as the regular operating and safety switches in common use in electric elevators, so that if the operator fails tobring the car to rest as the car approaches its limit of travel, the said automatic switch will do so in the same manner as if handled by the operator.

An object of our invention is to provide a safety switch which shall operate automatically, independently of slipping or stretching of the hoisting ropes or cables. Stop motion switches mounted on the machine cannot be relied on to always operate when the car reaches a predetermined position, owing to the slippage and stretching of ropes or cables on traction machines. Our invention in which the automatic switch is located on the car overcomes this objection. It is common to operate a set of limit switches in the hatchway by means of cams on the car or counterweight, such arrangement being independent of slippage or stretching of the cables, but our invention dispenses with these limit switches, and also does away with the extra wiring in the hatchway required for such limit switches.

Other objects of our invention, advantages incident thereto, and the exact nature thereof will appear hereinafter, the invention itself being defined in the appended claims in which are set forth the novel combinations of elements.

In the accompanying drawings,Figure l is an elevation view of a car switch and a automatic stop1notion switch combined Specification of Letters Patent.

Patented Nov. 9, 1915.

1911. Serial N0. 643,083.

therewith and constructed in accordance with the principles of our invention; Fig. 2 is a sectional side elevation view of the stop motion switch shown in Fig. 1; Fig. 3 is an elevation View showing a modified form of stop-motion switch and switch operating mechanism arranged under the car; Fig. is a view showing still another form of automatic switch operating mechanism which we consider the preferred construction; and Fig. 5 is a diagrammatic view of an electric elevator system embodying our invention.

Broadly speaking, our invention comprises a stop-motion switch carried by the elevator car and arranged to be actuated by means of cams located in the hatchway, preferably at or near the limits of travel of the car, (or at other predetermined points), the arrangement being such, that as the car approaches the limit of travel, in either direction, the stop motion switch is automatically operated to effect certain changes in the electric circuits controlling the operation of the hoisting mechanism, thereby causing the car to come gradually and with certainty to rest at a predetermined point, regardless of such conditions met with in practice as variations in speed or load, over-running, slipping or stretching of cables, etc.

In elevator installations, it is customary to provide limit switches in the hatchways or upon the hoisting machine. The hatchway limits are arranged to stop the car at its limits of travel upon being engaged by the car or its counterbalance weight, while the machine limits where used operate to stop the car after the cable sheave or drum has made a predetermined number of revolutions. "The stop produced by the operation of either of these limits is modified by the slippage or stretching of the cables or other conditions. Our invention provides means actuated whenever the car reaches a certain predetermined point in its travel, the operation being independent ofslippage and other conditions which modify the operation .of automatic stop devices heretofore in use.

Referring now more particularly to the drawings, F ig. 1 illustrates an embodiment of our invention, in which the car switch 11. and the stop motion switch 12 are mounted on the floor 1?) of the elevator car by means of the standards 14, which are preferably hollow to contain the electrical conductors The car switch 11 comprises the hand lever 16, the contact plate 17, and the contact fingers 18, 19, 20, 21, 22, 23. The contact fingers are suitably mounted to make electrical connections with the contact plate 17 as the hand lever 16 is moved tothe right or left of the central position, and such connections effect the movement of the elevator car in one direction or the other, depending on which direction the contact plate 17 is moved.

One type of the stop motion switch 12 is shown by Figs. 1 and 2, in which a series of cams 24, 25, 26, 27, 28, 29, are mounted upon the shaft 30 and are angularly adjustable thereon. Corresponding with these cams are the levers 24', 25', 26, 27, 28', 29', mounted on shaft 40, and each of which carries a Contact pin or roller 37 adapted to bridge a pair of stationary spring contacts 38 mounted on the insulating plate 41. The contacts 38 are connected to binding posts 39. The levers 24 to 29' are provided with cam projections 42 in the path of the corresponding cams 24 to 29, so that as the shaft 30 is rotated, the cams 24, etc., operate the levers 24, etc., in succession. A gear wheel 31 is fixed to the shaft 30, and meshes with a toothed segment 32 secured to the shaft 33. An arm 34 which has a bifurcated extremity is also secured to the shaft 33. A bar is suitably mounted to slide in brackets 43 and carries a pin or projecting member 36 which engages the bifurcated end of the cam 34. The bar also carries rollers 44 at its endsso that the operation of the stop motion switch 12 is effected by the engagement of these rollers 44 with suitably placed cams or pro- ,jections A. Centering springs 45 are operative to center the bar 35. The operation of this arrangement will be readily understood. The control circuits from the car switch contacts are closed through the stop motion switch contacts. WVhen a predetermined point in the travel of the elevator car isreached, one of the rollers 44 is engaged by its cam A, thereby moving the bar 35 in the direction of its length. The pin 36 moves the bifurcated arm 34 and rotates the shaft 33 and through the intermediate toothed gears 32 and 31 rotates the shaft 30.

' When the shaft 30 is rotated the cams 24 to 29 are carried with it and engage the corresponding levers 24 to 29, and operate the latter, as already explained, to break the electrical connectionsthrough the contact fingers, thus opening the control circuits from the car switch 11 and stopping the elevator car.

The hatchway cams A may he made either with a constant or variable angle, but preferably the latter. As shown, each cam has a gradually increasing angle and forms substantially a hyperbolic curve. This form of angular velocity which insures the proper interruption of the control circuits. 3. The roller 49 is on a steep portion of the cam when the final stopping contact is operated and the vertical stopping-point of the car is therefore dependent as little as possible on any horizontal motion of the car due to clearance in the car guides.

Another form of apparatus contemplated by our. invention is shown by Fig. 3 in which the stop-motion switch 46 is located beneath the car 50. The bar 47 is also mounted beneath the car by means of the hangers 48, and is provided with rollers 49 at its ends, and springs 45 for returning the bar to a central position after being operated. I A rack 51 on the bar 47 is adapted to engage a pinion 52 mounted on the shaft 53 of the stop motion 46. A drum 54 rotates with the shaft 53, and, when in the position shown is in electrical connection with contact members 55, 56, 57, 58, 59, 60, which bear against the drum. When the contact bar 47 is moved the rack 51 rotates the pinion 52, thereby causing the drum 54 to rotate and break contact with the contact members 55, 56, 57 or 58, 59, 60 in the order named, thus providing means for opening the' electrical connections from the car switch as previously stated. It is to be un; derstood that there may be any desired number of contact members, although only a limited number is shown in the drawing.

The rollers 49 of the bar 47 are engaged by v wedge-shaped projections or cams 61, 62 which are suitably placed to efiect the movement of the bar 47 at predetermined points. Fig. 4 illustrates the preferred form of stop motion switch mechanism. As here shown, a casing 78 is provided in which is within the casing, is a cam 69, adjustable" angular-1y and also longitudinal-1y of the shaft. The segment 63 is provided with a depending arm 66 to the lowerend of which is pivoted a buffer wheel or roller 67 adapted to coiiperate with the cam A. The end plate of the casing is formed with a lug 71 in which is secured a ring or bushing 7 9. A sleeve 74 is threaded at its upper end into the bushing 79. A rod 75 extends loosely within the sleeve 74 and has secured to its upper end a chain 73. The upper end of the chain is attached to a lug-72 on the segment 63. A coil spring is mounted on the sleeve 74 and rod 75 and bears at its upper end against 'the bushing 79. A washer 76 retained in position by lock nuts 77 on the lower threaded end of the rod 75 forms an adjustable stop for the lower end of the spring.

lVithin the casing is a series of switch levers, as 80, pivoted on a shaft 86. Associated with each switch lever is mechanism as will now be described in connection with the lever 80. A switch contact 83 is mounted in the upper end of the lever 80, and suitably insulated therefrom. A flexible conductor 89 is provided with a terminal clip 87 by means of which it is electrically connected with the contact 83, lock nuts 88 serving to secure the clip 87 to the stem of the switch contact. The opposite end of the conductor 89 has a terminal lug 90 connected to a binding post 90. Cooperating with the contact 83 is a stationary contact 84 secured within the contact holder 85. The latter is mounted on an insulating base 96. The switch lever 80 carries an arm 81 on which is pivoted a roller 82 in the path of the cam 69. The switch lever 80 is held in its closed position by a spring 92 one end of which is held in position by a stud 91 on the switch lever, and the other end of which surrounds a stud 93 which, as shown, is threaded into a wall or flange of the casing. The stop-motion switch here shown (Fig. 1) is preferably located on top of the elevator car, or may be located in any convenient position to cooperate with the cams in the hatchway. It will be understood that there is a cam Aat each end of the hatchway, both cams being in position to be engaged by the roller 67.

In operation the roller 67 engages the cam A and is carried to the left to the position (57. During this movement the gear (it rotates the pinion 65 in a counter-clockwise direction, carrying with it the cam 69. The latter engages the roller 82 and opens the switch, the roller 82 being forced back to the position 82, and the posts 87,88 taking the positions indicated at 87, 88.

Although Fig. at shows but one switch it will be understood that as many pairs of switch contacts may be employed as are shown diagrammatically in Fig. 5 or as are necessary or desirable to effect the proper operation of the automatic stop mechanism. This requires simply a duplication or multiplication of the switch levers, contacts and other parts within the casing. The additionalcams 69 would be arranged to secure the operation of the switches in unison or their successive operation as in the constructions shown in the other figures. The number, position, form, and arrangement of the cams on the shaft 68 may of 65 course be widely varied as may also the form of switch apparatus operated by the cams, many specifically different forms of cam mechanism for effecting the operation of a series of switches being at present in vogue.

A diagrammatic representation of our invention in connection with an electric elevator is shown by Fig. 5 in which the stopmotion switches S are mounted on top of the elevator car C. The car switch K efiects the operation of the reversing switches R and R, which complete circuits for the motor M in the ordinary manner. Other controlling apparatus, such as the brake B, accelerating magnet A, load magnet L, fast speed magnet FS, and potential switch P are well known in the elevator art and need only be briefly referred to. The magnet winding i is in series with the reversing switch magnets, and controls the admission of an energizing current to the electro-dynamic load magnet L. The extra field E is connected across the motor armature through the sectional resistance 99 and the fast speed magnet contacts 91. The car safety switch G and the slack cable switch H, as well as the stop resistance which is only in circuit whenthe opening of the potential switch P closes the contacts 96, are all conventionally shown. The cams 100 and 101 are suitably located in the elevator hatchway to engage the lever 118 of the stop motion switch upon the upward or downward travel of the elevator car. The stops 115, 116 prevent the rotation of the contact arms 117, 113 in the wrong direction and the spring 11% is adapted to return thesaid arms to their normalposition after being operated.

In order that our invention may be more readily understood the operation of the embodiment shown by Fig. 5 will be explained. Turning the hand lever of the car switch K in the direction marked Up a circuit is first closed from the positive main through car switch contacts 105, 107, stop motion switch contacts 103, magnet winding of reversing switch R, magnet winding N, and thence to the negative main. This causes the reversing switch It to be operated, thereby releasing the brake B and closing the field and the armature circuits to the motor M in a direction to cause the motor M to raise the elevator car 0. To increase the speed of the motor M the car switch hand lever is rotated still further to make connection with contact 106 which closes a circuit through the winding of fast speed magnet F8. The operation of the fast speed magnet short circuits the resistance 108 and causes the accelerating magnet A to be energized; This accelerating magnet A operates in a well known manner to short cir-- cuit resistances 109, 110, and series field windings 97, 98 in SLICCBSSIOIL The load magnet L is connected across the armature of the motor M and can only be energized when the magnet N is not energized, that is, when neither reversing switch is energized. The load magnet L short circuits a portion of the sectional resistance 99 dependent on the speed of the motor and the extra field E is excited in accordance with the counter electro-motive force of the motor M. This circuit through the resistance 99 and extra field E constitutes an electro-dynamic brake circuit. a

Assuming that the elevator car is nearing the predetermined stopping point in the up direction, the wedge shaped cam 100 in the elevator hatchway engages the buffer roller 111 of the stop motion switch S causing the lever 118 to be rotated and the contact arm 113' to be moved in accordance with the movement of the roller 112 on the lever 118. The movement of this contact arm 113 which diagrammatically represents our preferred type of stop motion switch separates the contacts 102, 103, 101, thereby breaking the circuit connections controlling the operation of the motor M. Separating the contacts 102 opens the circuit through the fast speed magnet FS, deenergizing that magnet. causing the resistance 108 to be re-inserted in the motor circuit, and breaking the energizing circuit through the accelerating magnet A. The latter drops its contacts and re-inserts the resistances 109, 110 and the se R to be opened and cut off the current supply to the motor, effect the application of the brake B, establish the electro-dynamic brake circuit, and establish a circuit for the load magnet L, the latter operating to regulate the resistance in the electro-dynamic cir cuit and also the strength of the extra field E.

Separation of the contacts 104: opens the circuit through the holding coil of the potential switch P, thereby breaking all circuit connections to the motor M and to the controlling apparatus.

The contact arm cam 101 engaging the buffer-roller 111 on the downward travel of the elevator car C, similar to the operation of the contact arm 113, uponthe upward motion of the car C. It is to be understood that the construction shown by Fig. 5 is merely a diagrammatic representation of our preferred type of stop-motion switch.

It will be observed that the automatic switch contacts 102 and 103 are in circuit with the controller contacts 106, 107, so that the operation of the stop-motion switch has the same effect as moving the controller K to center. In addition the automatic switch opens the potential switch circuit also in case 117 is operated by the the opening of the contacts 102 and 103 do not bring the car to rest before the contacts 104 have been separated. It will be seen from the above relation of the contacts in the automatic switch and the controller K that the stop-motion mechanism might be arranged to operate the manual controller K instead of a separate switch, and our in-' vention contemplates such an arrangement. The construction shown, however, has the advantage that it permits additional safety or controlling circuits to be controlled by the automatic switch, or any desired order in the control of the circuits independently of the manual switch. l/Vhatever arrangement is employed the wiring to the car switch is also used for the automatic stop-motion switch, thereby dispensing with the extra wiring necessary with the usual arrangement of limit switches in the hatchway.

We wish not to be limited to the exact construction, combination or arrangement of the several parts, as it is evident that-those skilled in the art may make various changes without departing from the spirit and scope of our invention.

l/Vhat we claim and desire to secure by Letters Patent of the United States is 1. An electric elevator comprising in combmation an electric motor, an elevator car,a manual controller in the car, an automatic controller carried by thecar comprising a rotary shaft and switches actuated thereby, motor controlling circuits extending through said controllers, a safety circuit extending through the automatic controller independent of the manual controller, and means for operating the automatic controller shaft first to interrupt said controlling circuits and thereafter open said safety circuit.

2. In an electric elevator, the combination of acar, an electric motor connected there with, a manual controller in the car, an automatic controller carried by the car comprising a rotary shaft and switches actuated thereby, motor controlling circuits associated with both of said controllers, and means for effecting a gradual operation of said automatic controller shaft first to slow down and then stop the motor.

3. In an electric elevator, the combination of a car, an electric motor connected therewith, a manual controller in the car, an automatic controller carried by the car comprising a rotary shaft and switches actuated thereby, motor controlling circuits associated with both of said controllers, and means for effecting a gradual operation of said automatic controller shaft when the car reaches a predetermined point in its travel first to slow down and then stop the motor.

4:. In an electric elevator, the combination of a car, an electric motor connected therewith, a manual controller in the car, an automatic controller carried by thc car comprising a rotary sha'rt and switches actuated thereby, motor controlling circuits associated with both of said controllers, and automatic means operable when the car reaches a predetermined point in its travel for eifecting a gradual operation of said matic controller shaft first to slow down and thereafter stop the motor.

5. In an electric elevator, the combination or" a car, an electric motor operatively connected therewith, controlling circuits for said motor, automatic means carried by ME car for effecting the successive opening and closing of said controlling circuits, said antomatic means comprising a plurality of switches, a single means for controlling said switches, and a cam in the hatchway for actuating said switch-controlling means.

6. In an electric elevator, the combination of a car, an electric motor operatively connected therewith, controlling circuits for said motor, a plurality of switches carried by the car arranged to open and close said controlling circuits in successive order or sequence, a rotary member common to all of the switches for actuating the latter and automatic means for operating said rotary member.

7 In an electric elevator, the combination of a car, an electric motor operatively connected 'therewith, controlling circuits for said motor, a plurality of switches carried by the car arranged to open and close said controlling circuits in successive order or sequence, a member common to all of said switches for actuating the latter and automatic means operative at predetermined points in the car'travel for efiecting the operation of said switch-actuating member.

8. In an electric elevator, the combination of a car, an electric motor operatively connected therewith, controlling circuits for said motor, a plurality of switches carried by the car arranged to ,open and close said controlling circuits insuccessive order or sequence, means common to said switches for actuating the latter, and cams positioned adjacent the car travel for efiecting the auto matic operation of said switch-actuatmg means at predetermined points in the car.

travel.

9. in an electric elevator, the combniation of a car, an electric motor operatively connected therewith, a main line circuit, an electro-responsive device adapted to close a circuit between the said main line and motor, an electro-responsive device for controlling the speed of the motor, a plurality of switches on the car adapted automatically to efiect the successive operation ct said GlGGZTG'PQ- pensive devices, common actuating means for said switches, and means adjacent path or" car travel for operating said switchactuating means.

10. in an electric elevator, the combination of a car, an electric motor operatively connected therewith, a main line circuit, an electro-responsive device adapted to close circuit between the said main line and motor, an electro-responsive device for controlling the speed of the motor, a plurality oi switches on the car automatically operated at predetermined points in the car travel for effecting a successive operation of said electro-responsive devices, a member common to said switches and adapted to actuate the latter, and a stationary cam for effecting the operation of said switch-actuating member.

In testimony whereof, I have signed my I name to this specification in the presence of two subscribing witnesses.

DAVID L. LINDQUIST. Witnesses F. O. Dnrron, E. H. S'ru'rs. 

